KX250F vs KDX 200

[BPJNT]

Just wondering how the KXF is in the woods, I currently have an 02 KDX 200, but looking at picking up 2nd bike. Really looking hard at the 03 KX 250. I'm a 2 stroke guy and will find it hard to change to 4 stroke. But always will keep an open mind. I ride 50/50 Woods/MX.

I saw where some GNCC guys were going to use the KXF next year.

Thanks :)

 

[CaptainObvious]

The KDX is a great $4,500 bike ($3,500 plus $500 to $1,000 in required mods to get into the 21st century), but it's just no match for any of the new 250cc four strokes. If you have the means to buy a KXF, then I would suggest the KXF over the KDX. With the right suspension mods and a light kit the KXF would be an awesome woods bike.

In fact, I'm hoping that Kawasaki does this exact same mod and calls it the KDX250F.

 

[gwhII]

... With the right suspension mods and a light kit the KXF would be an awesome woods bike.

In fact, I'm hoping that Kawasaki does this exact same mod and calls it the KDX250F.

In the Feb '04 issue of Dirtbike there's an article on a 302cc KXF built by RPMs as a cool trailbike. Honda has also thrown the gauntlet down with the CRF250X so Kawasaki could see a reason to build one.

I like the idea of a four stroke but I'm concerned that at 230# that I'm too heavy for one.

Best,
Greg

 

[Smit-Dog]

There's no doubt that a woods KXF / 4-stroke KDX will come in time, but there are still some teething pains the KXF needs to get through first.

 

[coleman]

230 is a little heavy for a 250 four stroke but if you're riding a kdx at 230 then you will have no problems with a 250f. I used to have a kdx and I switched to a 2001 yz250f. Really glad I switched. The 250f has way more power than my kdx ever had plus the suspension, brakes and ergos are much better.

 

[KDXFreestyle]

theres only 1 bad thing I read about the KXF... It overheats, but I heard PC was making oversized radiators. :flame:

 

[Twiztid One]

a buddy of mine just got one and as soon as all this snow and ice disapears i'm gonna give a good test ride . its only a matter of time and 2 strokes will be history and that will be a sad day .

 

[tall1]

KX250F Enduro.. See Picture

Kawasaki doesn't come out with new models unless they have to. The KX250F Enduro,is most likely coming soon, thanks to the new EPA standards coming in 2006. I have never riden a four stroke that I liked, This is truly a sad event :|

 

[BPJNT]

Tall1

Where did you find that picture?

What do you know that the rest of us don't, looks like an awesome bike in the pic. Give us some details. Is it just a KXF with a light or is there more?

BPJNT :)

 

[Mrobbins]

Even has a kickstand. Gotta like the supermotard version sitting next to it too.

 

[tall1]

Where did you find that picture?

What do you know that the rest of us don't, looks like an awesome bike in the pic. Give us some details. Is it just a KXF with a light or is there more?

BPJNT :)

The picture was taken from the December Dirt Rider Magazine. Kawasaki was displaying this bike and a KX250 in SuperMotard trim at the 61st Milan Motorcycle Exhibition. New EPA standards go into effect in 2006. My guess is the four stroke will meet emission standards easier than a two stroke. Even so expect the four stroke model to de tuned to meet the new emission/noise standards. Expect the KDX line to disappear from the USA soon.

 

[Fred T]

Fredette is developing one and will be one one this season.

 

[kdxman15]

why cant i see pitures now. it says im not aloud.

 

[gwhII]

230 is a little heavy for a 250 four stroke but if you're riding a kdx at 230 then you will have no problems with a 250f. I used to have a kdx and I switched to a 2001 yz250f. Really glad I switched. The 250f has way more power than my kdx ever had plus the suspension, brakes and ergos are much better.

After this past weekend, I'm not worried about getting a KX250F for a trailbike. I pulled my topclamp off and cast into it is "86 KX125" which I'm assuming means that the current KDX suspension (at least front) is patterned after a circa 1986 KX125. If this one handles my weight just fine, then so will a KX250F.

As for power, I agree that from everything I've seen, the 250Fs (all of them) make as good horsepower numbers as a modified KDX200 but I wish they'd also show the torque curves. Given close hp, I think that'll matter more to us heavier riders.

Best,
Greg

 

[CaptainObvious]

You can extrapolate the torque curve by taking the HP number, multiplying it by 5252 and then dividing the result by the RPM.

Generally speaking, the four strokes have more area under the HP curve, a clear indication that they are making great torque. For example, two engines (a 2-stroke and a 4-stroke) make the same 30 HP peak HP. The 2-stroke makes 90% of its peak between 7,000 and 9,000 rpm but the 4-stroke makes 90% of its HP between 5,000 and 11,000. This greater area under the curve is due to a torque curve that reaches its maximum value early in the rpm range and is able to sustain that value for a considerable period of its rpm range.

 

[m0rie]

You can extrapolate the torque curve by taking the HP number, multiplying it by 5252 and then dividing the result by the RPM.

Generally speaking, the four strokes have more area under the HP curve, a clear indication that they are making great torque. For example, two engines (a 2-stroke and a 4-stroke) make the same 30 HP peak HP. The 2-stroke makes 90% of its peak between 7,000 and 9,000 rpm but the 4-stroke makes 90% of its HP between 5,000 and 11,000. This greater area under the curve is due to a torque curve that reaches its maximum value early in the rpm range and is able to sustain that value for a considerable period of its rpm range.

Yeah, what he said :laugh: .

-Maurice

 

[Matt90GT]

Keep in mind that the 250F is a racebike.

The 1 piece waterpump and oil filter cover has a reason according to kawasaki. The filter will last the life of the top end. So when you change the top end after 3 rides, you will drain the coolant at the same time.

This is direct from Kawasaki.

 

[m0rie]

Keep in mind that the 250F is a racebike.

The 1 piece waterpump and oil filter cover has a reason according to kawasaki. The filter will last the life of the top end. So when you change the top end after 3 rides, you will drain the coolant at the same time.

This is direct from Kawasaki.

Ouch, i think thats while i'll wait for the KDX250F before I pick one up.

-Maurice

 

[fuzzy]

They will have to build it to keep up with Yamaha's WR trend.....

That filter design sounds wack! Well no suprise as it's a POS Suzuki with green plastic...

When all Kawi 2-strokes are gone, and the Kawi/Squid merger is complete you'll never see me on a green bike again :whiner: Well, you'll see me on a non-production green 2-stroke from time to time!!

I've already cried about this back in 98 when Yama took my beloved YZ/WR into the 4-stroke world :debil:

 

[gwhII]

You can extrapolate the torque curve by taking the HP number, multiplying it by 5252 and then dividing the result by the RPM.

Generally speaking, the four strokes have more area under the HP curve, a clear indication that they are making great torque. For example, two engines (a 2-stroke and a 4-stroke) make the same 30 HP peak HP. The 2-stroke makes 90% of its peak between 7,000 and 9,000 rpm but the 4-stroke makes 90% of its HP between 5,000 and 11,000. This greater area under the curve is due to a torque curve that reaches its maximum value early in the rpm range and is able to sustain that value for a considerable period of its rpm range.

Forgot to say thanks for the torque/HP formula. That'll come in handy.

Apologies for getting off on a tangent but a generic engineering-type question:

I see what you're saying. In the explanation above, are you also making displacements equal? I'm trying to figure out how much of the curve's shape is because of disparities in displacement or caused by the designer's choice of bore size and rod length and port sizes, etc, to tune an engine for power delivery in a certain RPM range and how much is because of a 2-stroke's or a 4-stroke's natural behavior.

Can someone recommend any reasonable texts (I haven't been in college for 10 years) to get a grasp on the basic principles?

Best,
Greg

 

[m0rie]

They will have to build it to keep up with Yamaha's WR trend.....

That filter design sounds wack! Well no suprise as it's a POS Suzuki with green plastic...

I couldn't disagree more. I love my brother's KLX400 which is just a re-badged DRZ400. Lots of power and tractability. About the only thing I don't like about it is the weight.

-Maurice

 

[CaptainObvious]

Well the faux example I gave above assumes a 125 2-stroke and a 250 4-stroke.

As far as reading material, per haps Rich Rohrich or Eric Gorr could suggest something.

 

[NYkdxer]

gwh, I'd suggest you read "Two-Stroke Tuner's Handbook", by Gordon Jennings. It's aimed at the two-stroke enthusiast and may help answer your questions. I got it out from the local library and haven't finished reading, but its a great text so far. Very in-depth, which i like :)

 

[CaptainObvious]

gwh, I'd suggest you read "Two-Stroke Tuner's Handbook", by Gordon Jennings. It's aimed at the two-stroke enthusiast and may help answer your questions. I got it out from the local library and haven't finished reading, but its a great text so far. Very in-depth, which i like :)

Great suggestion. :thumb: I forgot all about that book.

 

[gwhII]

Thanks, NY and RV. I read an article about this same topic by Kevin Cameron the other day and he mentioned Jennings' book. I've been looking for it and it's hard to find. He also mentioned books by Alexander Bell and a couple others. I can let you know what else I find if you're interested.

Best,
Greg